Sidney f



(N o Model.)

S'. F. SHELBOURNE.

, ELECTRICAL CONDUCTOR.

No. 313,380. Patented Mar. 3, 1885.

Inventor:

UNITED STATES PATENT OFFICE.

SIDNEY F. SHELBOURNE, OF NEYV YORK, N. Y.

ELECTRICAL CONDUCTOR.

SPECIFICATION forming part of Letters Patent No.8l3,380, dated March 3,1885.

(No model.)

To all whom it may concern:

Be it known that I, SIDNEY F. SHELBQ'URNE, a citizen of the UnitedStates, residing in the city of New York and State of New York, haveinvented a new and useful Improvement in Electric Conductors; and Ihereby declare that the following is a true, clear, and exactdescription of the same.

This invention relates more particularly to that class of conductorsdesigned to convey powerful currents of electricity, as in the case ofthe electric light and automatic telegraphy, and which are required tobe heavily insulated in order to prevent the diversion and escape of thecurrent to adjacent conductive media by the rupture of a thinnerinsulation. Hitherto such conductors have been insulated by one of twomethodsfirst, by a heavy covering of gutta-percha, caoutchouc, or otherplastic substances, forced from a reservoir through dies around thewires, or, second, by several coverings of braided fiber saturated withor having superimposed upon them a fireproofing-paint or semi-insulatingmaterial. Both these methods have proved expensive, the first by reasonof the cost of the materials employed, and the second because of the labor and time required in the details of the several braidings and theapplication and drying of the saturation or fireproofing materials;also, in the methods described the conductor itself has usually been ofa single rigid wire, which has been found most desirable in securing aneven and uniform coating of the gutta-pereha or other material upon it.

For underground conduction, where the greatest flexibility in theconductors is desirable to enable them to be drawn readily into tubes orconduits, such conductors have been found impracticable, because theirrigidity and irregularities or unavoidable bends or deviations from astraight line make it difficult or impossible to draw them in or out ofconduits, except all together in a group. Besides, the fiber-surface ofthe insulation has usually been abraded and nearly destroyed by thedragging contact with the rough interior of the tubes within which theconductors were being introduced.

To obviate the several objections mentioned, I make a conductor asfollows: The copper eonductorcore is composed of any number of smallwires twisted together into a rope of a size to obtain the requiredconductivity, as

has hitherto been done in' submarine telegk raphy and some other cases.This conductor is then placed in a machine by which a multiple windingin one operation of coarse jute or similar fiber builds up around theconductor the insulation to the required thickness. The threads orstrands of fiber as they pass onto the conductor are made to submergeinto a melted insulating material, which becomes solid on cooling,preferably the petrapitta compound described in Patent No. 275,422,granted to me April 10, 1853. From the winding operation the conductorsare made to pass through grooved wheels or dies, by which theirinsulation is made round and uniform. A single heavy braiding is thengiven the conductor around its insulation-windings, which braidingitself being saturated with insulating ma terial, and the conductor asthus finished being passed through a lead press, it receives and isinclosed within a uniform and continuous jacket or close-fitting tubingof lead, which protects the insulation both from exterior moisture andfrom abrasion in the operation of drawing the conductors into theirsubterranean tubes or conduits, at the same time securing their greatestpossible flexibility.

In the drawings, Figure 1 shows a cross section, and Fig. 2 alongitudinal elevation, of the improved conductor, like lettersreferring to like parts in both the figures, in which Letter a is thecopper-rope conductor; 1), the multiple-winding insulation; 0, thebraiding inclosing such insulation, and (l the lead jacket or tubeinclosing the whole.

\Vhat is claimed as new is 1. A flexible electric conductor composed ofthe following elements: a copper core of several small wires forming aropeconductor, an insulation about the same formed of multiple windingsin bulk, of jute or other fiber saturated with a melted insulatingmaterial, a braiding of fiber inclosing such insulation,

and a jacket or tubing of lead inclosing and protecting the Whole,substantially as described.

2. An insulation for electric conductors built up around such conductorswith multiple windings of fiber, in combination with a saturation ofsolidifying insulating material and a braiding surrounding and inclosingthe same, as set forth.

tric conductor consisting of a rope-wire core, a multiple fiber windingin bulk with saturation of melted insulating material about said core,and a braiding inclosing such insulation,

with a jacket or outer shield of lead, as and I 5 for the purpose setforth.

SIDNEY 1*. SHELBOURNE. Witnesses:

It. P. GIIRIs'rIE, F. S. TYLER.

